The present invention has great utility in many varied settings. For example, the apparatus may be used in the "house arrest" or "home parole" setting. In that case, it is critical that the person remain at home or within prescribed geographical limits. Alternatively, the whereabouts or medical condition of elderly or infirm persons might be monitored. The present invention provides such a device which is capable of monitoring position as well as certain health related parameters such as heart rate, blood pressure or the like. The present invention is not however limited to the monitoring of individuals, rather it is applicable to monitoring any mobile object. For example, the present invention can be used to detect and track stolen cars.
The term "environmental information" will be used herein to refer to information which may be gleaned from the person or object wearing the device, or his/its surroundings. Examples of such environmental data may be, but are not limited to, sound, temperature, motion, and the like.
There is a current move in our nation to stem the growth in the crime rate by building more prisons and hence incarcerating more people. Part of this stems from pressure from the public to keep hard core or habitual criminals locked up for the full length of their sentence. This pressure is balanced against an even stronger push by the public to keep cost of government down.
One recent solution to this dilemma has been "house arrest" technology, which allows minor offense sentences to be carried out in the home. The system consists of a transponder which the convicted person must wear, which must be present when that person is called by the police to verify presence at home or work. One severe drawback of this process involves use of man-hours and the associated cost of doing on-site inspections to ensure that the monitored persons are actually where they say they are. Additionally, there are several ways to fool the system if this manual checking is not implemented. Consequently, there is some risk that a prisoner could get loose. The cost of "house arrest" is balanced against the cost of housing low risk prisoners. While a net savings is realized, it is not large, and the funding must be justified separately.
Thus, there is a great need for an apparatus which would reduce, eliminate, or postpone the need for more prisons. Such an apparatus would accomplish tightened security of prisoner tracking, with virtually no risk of fooling the system, and would allow limited freedom of prisoners to rehabilitate themselves via controlled community interaction and limited freedom of travel. To state the obvious, a working taxpaying prisoner who is effectively restrained at little cost to the taxpayer is preferable to incarceration, where no true rehabilitation is accomplished and costs are becoming astronomical. Such a system is implemented with the present invention.
Additionally, some elderly or infirm persons need constant monitoring of their location and/or of certain medical parameters. Such parameters might include blood pressure, heart rate or the like. The present invention provides a means for accomplishing such a monitoring without the need for constant supervision and for providing immediate "real time" notification of the proper medical authorities. The system also provides a means for monitoring the status of an automobile in order to provide a deterrent to theft. For example, the apparatus can be attached to the car in some "hidden" spot to avoid or decrease the potential for removal. The motion, temperature, and position monitoring functions can then be used to detect theft or attempted theft of the auto. For example, the occurrence of motion or the detection of rising temperature might be indicative of the unauthorized starting of the car. With the position determining function, if the car is stolen, it can be tracked.
The invention disclosed herein overlaps several technical areas involving not only the provision of positioning data remotely of the sensor, but also of providing additional remote monitoring of other environmental factors such as temperature, audio signals, blood pressure, heart rate and the like.
One example of a prior art device providing relative positioning information is Kotoh, U.S. Pat. No. 4,673,936 issued Jun. 16, 1987. Kotoh discloses a rescue transmitter apparatus adapted to be worn on a person's wrist. Kotoh's transmitter transmits a microwave signal which may be received by a search and rescue craft. Relative position may be determined by using a directional antenna to determine the direction of the strongest signal. No absolute positioning or other, environmental information is available.
Another prior art device is illustrated in Darnell et. al. U.S. Pat. No. 5,043,736 issued Aug. 27, 1991. Unlike the Kotoh device, Darnell's transmits absolute, (i.e. geographical latitude and longitude), position information. Darnell discloses a hand held apparatus which contains both a GPS receivers as well as a cellular telephone transmitter. The hand held unit receives the GPS signals, generates a reference timing signal, and identifies the time difference therebetween. As is well understood in the art, this time difference is indicative of the distance between the receiver and the GPS satellite. Thus, from knowing the time differences from a series of satellites, an absolute position may be determined. This time difference information, determined by the hand held unit, is transmitted to a remotely located base unit. This base unit then uses the time difference information to determine the position of the remote unit. While the Darnell system is adapted to determine and transmit absolute positioning information, no other environmental information is detected or transmitted.
Several prior art devices have been proposed in the field of prisoner monitoring in the house arrest scenario. One of these is Pauley et. al. U.S. Pat. No. 4,885,571 issued Dec. 5, 1989. Pauley discloses a device (a "tag") which is adapted to be worn on the person subject to the house arrest. The device transmits periodically to a field unit which then communicates with a remotely positioned central processing unit. The communication of information from the "tag" to the field unit consists of an identification signal which is an encoded message identifying the "tag" from which the signal is sent. No other positional or other data is sent. Verification that the person is remaining within the prescribed limits imposed is inferred simply by the fact that the signal from the "tag" is being received by the field unit. Since the "tag" has a limited transmission range, reception of the signal transmitted therefrom by the field unit is possible only when the field unit is within the "tag's" transmission range. Thus, no absolute or even relative positioning data is available with the Pauley apparatus. Rather, a simple in-range/out-of-range indication is available.
U.S. Pat. No. 5,493,694 discloses a fast response system for a fleet of vehicles. At a selected time, a central station broadcasts an interrogation signal requesting that selected vehicles in a selected group respond with the present location and status of each vehicle. The central station then ceases its broadcasts and waits a certain time interval for the vehicle responses. Using a protocol known by the central station and by each of the vehicle transceivers, each vehicle replies with the requested information during a particular consecutive time slot. Each transceiver has listened to the central station's interrogation signal and knows (1) whether it was one of the transceivers queried, and (2) if it has been queried, what its numerical position in the queue for responding to the query. If a particular transceiver is not among those queried, the transceiver ignores the interrogation signal and waits for the next interrogation signal. In this way, only transceivers whose numbers are broadcast or otherwise identified respond to the central station, and each such transceiver responds only in its allocated time slot.
When the central station receives a call requiring assistance, it broadcasts an incident message that includes the location of the incident and whatever is known about the incident. Each vehicle message unit receives the incident message, determines its present location and the distance from that vehicle to the site of the incident, determines if that vehicle can respond to the incident, and replies to the incident message by transmitting its present location and other pertinent information. The vehicle message unit transmits this reply if and only if the distance is less than a predetermined distance to the incident site.
U.S. Pat. No. 5,528,248 to Steiner et al. discloses a personal digital location apparatus for displaying the consumer's location on a map. The device is a hand held apparatus having a GPS antenna and receiver to provide location information, and is capable of using standard operating systems to run existing applications, and is capable of running programs written in high level languages to provide the consumer with a display of his location and relative locations and the attributes of map features proximate to the consumer. Nothing is this patent relates to the continuous monitoring and tracking of an individual remote unit by a central control station.
U.S. Pat. No. 5,541,845 to Klein discloses methods for monitoring the adherence of a vehicle to a planned route and/or planned time schedule, within a selected corridor in location and time, where the vehicle follows a selected route. The invention may use GPS, or other location determination system, positioned on the vehicle, to determine and store the present location of the vehicle. The vehicle communicates its present location, route status (on route or off route), schedule status (on schedule, ahead or behind schedule), and other relevant information, to a central station from time to time. The processor in the vehicle attempts to locate the vehicle on the route by correlating the route and schedule data with the current time of day and current vehicle position. A snap-to-route command is provided to identify the location on the assigned route that is closest to the vehicle's present location as determined by the on-board location determination system. It should be noted in FIGS. 4 and 5, steps 39 and 49, that non-adherence to the specified route or failure to meet a specified time schedule will cause the vehicle system to notify the central station.
While this patent discloses an on-board computer which continuously tracks the location of the vehicle within a time/location schedule, and notifies a central station of any "violation" of either the time or location schedule, there is no provision for uploading particular parameters from the central station as to the route or "corridor" to be followed. Second, there is no provision for storage of a "map" of the track of the vehicle throughout the course of a day or selected time period, which is subsequently downloaded to the central control station so as to map out the specific time and location of the vehicle along the route.
U.S. Pat. No. 5,552,772 to Janky et al. discloses a location determination system used to determine the present location of a firefighter at a fire site or the like. In one embodiment, the firefighter carries a unit that receives signals from a group of sources. A central station interrogates one or more of the units, each selected unit automatically responding by transmitting its location to the central station for further processing, storage or display. The system can accumulate and report on the accumulated time a firefighter is present in one or more designated sub-regions at a site, and can advise a person at the control station that a particular worker should leave a sub-region when an accumulated time exceeds a selected threshold.
The patent discloses another polling type system which requires the central station to interrogate the remote units to determine the location of a firefighter. The remote units do not have processors which can store location data, nor upload parameters, nor download map information showing past locations.
U.S. Pat. No. 5,568,119 to Schipper et al. discloses a method and apparatus for monitoring the current location of a remote unit. The current location of the unit can be checked at selected time intervals. The device is particularly addressed to "house arrest" situations where an arrestee wears a location determining (LD) unit that receives signals allowing determination of the current location of the LD unit and arrestee. The signal sources may be GPS type systems or ground base systems. In one embodiment of the invention the remote unit processes the information to determine the present location of the arrestee and transmits this information to a central station. In another embodiment, the remote unit does not process the information, but rather transmits the information to the central station for further processing to determine the present location of the arrestee. The central station compares the present location of the arrestee with the designated site in its boundary to determine if the arrestee is staying on the designated site. If the arrestee has moved off the site without prearranged permission, or if no intelligible response signal is received at the designated times, the central station promptly notifies the appropriate authorities. The remote unit may contain a tamper detection circuit that transmits an alarm if tampering is detected. Optionally, the remote unit may transmit the present position information in encrypted form.
FIGS. 6 and 7 both show flow charts of a procedure used to determine the present location of an arrestee, and which include the initial step requiring the central station to transmit an interrogation signal to the remote unit. Thus, these flow charts disclose a polling type system, which polls the remote units at desired intervals. The remote units transmit location information, and the central station processes, stores and/or displays the location of the remote unit.
This patent also discloses the periodic modification of parameters to provide "corridors" or timed schedules, which the arrestee must follow. This information is processed at the central control station and alarms or warnings are transmitted from the central station for failure to comply with these parameters.
U.S. Pat. No. 5,461,390 to Hoshen discloses a locator device useful for house arrests and stalker detection. This device relies on a "polling" type apparatus, wherein a polling message is sent from a central location to remote units, to determine the location of the remote units at the time of "polling". There is no disclosure of any capability of Hoshen to upload parameters to the remote unit, store accumulations of location data as a "map" in the remote unit, nor to download a stored "map" to a central station. In addition, since the Hoshen apparatus is a polling type device, there is no "real time" alarm for violations of preset parameters.
U.S. Pat. No. 5,416,695 to Stutman et al. discloses a method and apparatus for alerting patients and medical personnel of emergency medical situations. The patent discloses the use of host connected by a telephone network to a "subscriber" unit, and receives information from a remote patient by a "telemetry" device. The remote telemetry device on the patient collects location information (via GPS) as well as medical information and transmits the information to the host computer. Parameters in the host computer are set, updated, or otherwise changed by the subscriber via the communications network. When the information transmitted from the patient exceeds these set parameters, a warning is sent both to the subscriber and to the patient.
A panic button is provided on the telemetry device permitting the patient to directly contact the host computer and thereby transmit an alert. It is noted that the typical method of providing information from the patients to the host computer is by "periodic polling" of all of the sources by the host computer. (See column 6, lines 3-5).
U.S. Pat. No. 5,416,468 to Baumann discloses a plurality of individual remote units on persons, which transmit the location of that person to a "field unit" at periodic intervals. If the information is not received at the field unit within a predetermined time range, an alarm may be triggered. The remote units may include "detectors" which sense environmental conditions and may transmit this data in addition to the location data to the field unit.
However, the Baumann remote unit can only transmit information, and does not know whether it was received by the field unit. Since no information may be received by the remote unit, it cannot receive any instructions as to differing parameters or the like. Finally, the remote unit does not store tracked accumulated information.